MATH
posted by I need help. on .
Providence County covers 413 square miles of Rhode Island. If Rhode Island is 1045 square miles, What percent of Rhode Island's area is Providence County? Round to the nearest tenth.
Can somone like explain to me how to do this.

Divide and multiply the decimal answer by 100.
413/1045 = 0.395215
0.395215 * 100 = 39.5% 
A small resort is situated on an island that lies exactly 4 miles from P , the nearest point to the island along a perfectly straight shoreline. 10 miles down the shoreline from P is the closest source of fresh water. If it costs 1.8 times as much money to lay pipe in the water as it does on land, how far down the shoreline from P should the pipe from the island reach land in order to minimize the total construction costs?